Introduced KitKat statusbar alpha transitions to custom GB elements
On KitKat, the color opacity of statusbar elements depends on in what
mode statusbar is currently in. When translucent, icons have full
opacity (bright white) to have higher contrast while when statusbar is
opaque, they are a little bit dimmed to reduce contrast.
StatusBarIconManager now handles these alpha transitions and notifies
all registered icon manager listeners when transitions happen.